One aspect relates to a semiconductor component, and a power semiconductor component, having a drift zone and a terminal zone of a first conduction type and having a component junction between the drift zone and a further component zone.
In semiconductor components of this type, such as diodes, bipolar transistors or MOSFETs, for example, a space charge zone or an electric field propagates in the drift zone in the off-state case proceeding from the component junction, for example a pn junction or a Schottky junction. The ability of the drift zone to take up such a space charge zone and thus a reverse voltage present at the component is dependent on the doping concentration of the drift zone and the dimension thereof between the component junction and the terminal zone.
In the off state, that is to say when a high electric field is present in the drift zone, semiconductor components are susceptible to so-called cosmic radiation, which can lead in the extreme case to a destruction of the component. Primary cosmic radiation includes very high-energy particles which arise outside the Earth's atmosphere and which generate secondary particles, including protons and neutrons, when they impinge on the Earth's atmosphere. These secondary particles, which pass down to the Earth, can generate a local plasma of charge carriers when they impinge on a semiconductor atom of a power semiconductor component. If a high electric field is present at the component at the instant when this secondary particle impinges, then charge carriers are generated in high density as a result of impact ionization at this location, whereby a local avalanche breakdown takes place, which, within a few hundred picoseconds (ps), leads to a local flooding of the component, of the drift zone, with charge carriers. A local filament is formed.
The robustness of a component to withstand cosmic radiation can be increased by lowering the doping concentration of the drift zone of the component, in order to achieve a so-called punch-through doping (PT doping) of the component. In these components, however, the width of the drift zone (that is a geometric feature) should be increased in order to avoid current chopping during switching operations, that is to say a high gradient of the current flow, which can result in an intense voltage spike and in electromagnetic interference in leads. However, increasing the width of the drift zone brings about increased switching and on-state losses of the component.